The present invention relates to a two-cylinder rotary compressor having two compression chambers, and a method for manufacturing the same.
A two-cylinder rotary compressor, wherein two compression chambers are located along a rotational shaft, is well known as one of closed-type rotary compressors. The compression section of the compressor includes a first bearing, a first cylinder, a partitioning plate, a second cylinder, and a second bearing. These components are stacked on one another in the order mentioned. As in a single-cylinder rotary compressor, the rotational shaft of the two-cylinder rotary compressor extends through the first and second cylinders, and is rotatably supported thereby. A medium is compressed by eccentrically rotating a roller in each cylinder by means of the rotational shaft.
Japanese Patent Publication [Kokoku] No. 59-25880 discloses how to fasten compression section having the above structure. According to this reference, a first bearing and a first cylinder are aligned and secured to each other by means of first bolts. Then, a rotational shaft and a first roller are installed with reference to the secured first bearing and first cylinder. Thereafter, a partitioning plate is aligned with the first cylinder and secured to it by means of second bolts. Subsequently, a second cylinder is aligned with the partitioning plate and is then secured to it by a plurality of bolts. After mounting a second roller with reference to the second cylinder, a second bearing is aligned with the second cylinder and is then secured to it.
In the compression section which is assembled by stacking the components on the first bearing, two adjacent components can be aligned with each other with high accuracy. Even if there is an error in the alignment between the adjacent components, the error itself would not cause a serious problem in practice. However, such errors will be added together during the process of stacking the components, with the result that the first and second cylinders tend to be greatly misaligned. If the first and second bearings are not aligned with high accuracy, the reliability and efficiency of the compressor will deteriorate. In addition, as long as the components are secured one after another with reference to the first bearing, the assembly of the compression section is troublesome and cannot be performed with high efficiency.